Receptacles capable of holding fluid, such as measuring jugs, beakers and measuring cylinders, are well known. Such receptacles have wide ranging domestic and commercial applications. Consumers are familiar with their domestic, especially culinary, application.
Such receptacles are also commonly used in technical fields, notably in dispensaries and laboratories, and a wide range of receptacles are commonly used to dispense and hold particular quantities of fluid materials. Customarily, receptacles such as measuring jugs bear series graduations with differing volumes indicated by horizontal lines circling or marked across the side of the container. The user holds the receptacle in an upright position to fill it with an appropriate quantity of fluid, and dispenses the fluid by constantly tipping the receptacle and returning it to an upright position, until the fluid is down to the desired level as indicated by the horizontal lines or markings.
Further, when it is wished to pour a desired volume of fluid from such a receptacle, the liquid must undertake a series of intermittent small pours, which can only be quantity estimates or guesses in the absence of useable quantity indications during the pour, until the user reaches the desired level. It is extremely easy when having to guess the quantity every time to pour too much fluid out of the receptacle, especially when the user is in a hurry. This can have serious consequences, such as destroying the efficacy of a process. The problems of overfilling and repouring can also prove expensive if costly materials are used, or the pouring process has to be recommenced. The time-consuming nature of having to make a series of small pours is also a problem.
In addition, even if a user judges that the fluid has reached the right level and that the surface of the fluid is aligned with the line segment indicating a certain volume, the short length of the line segment and/or the jug not being held precisely upright results in known measuring receptacles proving inaccurate measuring devices, unable to dispense or hold accurate measures of liquid.
In some receptacles, measuring cylinders in particular, the inaccuracy of horizontal line segments as indicators of levels of liquids was attempted to be addressed by applying marking right around the receptacle. However, fluid is still poured from the receptacle in a series of small pours, with the receptacle being continuously tilted from pouring position to upright position so that the user can see how much more fluid has to be poured or retained in the receptacle to reach the desired level of fluid.
As the fluid approaches the desired level, the process is much more deliberate, careful and time consuming. Measuring jugs are not perfect spheres, so every time the jug angle is changed between the pouring and upright positions the liquid is disturbed producing waves and these have to be allowed time to settle before one can accurately check the alignment of the surface line with the desired indicator line. In addition, if the fluid being dispensed or retained in the receptacle is viscous considerable time is spent in waiting for the fluid to run down the inner surface of the receptacle and settle to enable a reading of the level to be taken.
A major problem with known receptacles such as beakers and cylinders as discussed above is therefore that the receptacle must always be returned from a tilted position when the fluid is being poured to an upright position, so that the fluid surface can be aligned with horizontal markings on the vessel, and the fluid level in the receptacle thus ascertained. This process is time consuming and inaccurate, and often results in more than the desired quantity of fluid being dispensed from the receptacle, or insufficient fluid retained in the receptacle when the operator is in a hurry. This may have disastrous consequences for either the domestic or industrial user.
An improvement on the prior art is the measuring jug shown in FIG. 1. This jug, being an embodiment of the present inventor's own New Zealand Patent No. 211520 possesses level indicator lines radiating from the pouring mouth across the entire surface of the jug. There is also the traditional and separate set of horizontal level indicator lines. The radiating lines are calibrated so that the user can measure the quantity of fluid being dispensed from the container while the container is tilted.
The radiating lines can thus be termed "pouring lines". In use, aligning the surface of the fluid with a pouring line ensures the same amount of fluid is retained in the container when returned to its upright position.
The horizontal lines ("filling lines") are intended to be used as a level or volume guide for filling the jug, and are ranged spatially on a central vertical axis.
The jug of New Zealand Patent No. 211520 permits a desired quantity of fluid to be dispensed in one continuous pour, without continuously needing to return the jug to an upright position to assess how much liquid has been poured. The user can always ascertain, even when the jug is tilted, how much liquid has been poured out and accordingly how much remains in the jug. This system significantly reduces the time taken to dispense liquid.
Although an improvement over known measuring devices, it is now acknowledged that use of the measuring jug in New Zealand Patent No. 211520 still has certain difficulties.
To the user, the two separate scales (ie. the pouring lines and the filling lines) on the jug surface may be confusing. A user may not appreciate the purpose of the pour lines, and may simply ignore them. The user may revert to the customary series of pours, returning the jug to its resting position to measure how much liquid has been poured. The correlation of the pour lines to the horizontal filling lines is accordingly not obvious. As a result, the users do not appreciate the utility of the invention, and the advantages it holds.
A further problem with the jug in New Zealand Patent No. 211520 is that respective pouring lines and filling lines are accorded their own numerical values. The consumer is accordingly faced with a jug surface bearing not only lines extending from the pouring mouth over the entire surface of the jug, but also numbers accompanying these lines. Being so apparently complicated in appearance, manufacturers are reluctant to make the high investment in tooling costs because of doubt about public acceptance of the jug in the market place.
Another disadvantage of the jug of New Zealand Patent No. 211520 is that the two scales--the pouring lines and the filling lines--radiate over the entire surface of the jug. The separate scales of lines must be accurately applied both to provide accurate correlation between pouring lines and filling lines, and to ensure those indicating differing levels are accurately spaced apart. This also holds true for the numbers. The extension of lines and numbers over the jug surface provides difficulties to manufacturers of the jugs--the lines and numerals must be efficiently applied so that manufacture is viable. Yet care must also be taken to ensure the lines are correlated properly, with the jug providing accurate measurements as a result. This process is time consuming, and may require extensive modifications to existing methods of marking jugs, or even the development of new technology.
In particular, there is considerable visual confusion at the pouring mouth of the jug where the lines all converge.
It is accordingly an object of the present invention to overcome the foregoing problems and provide the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the ensuing description which is given by way of example only.